Unitary hooded electrical contact

ABSTRACT

An electrical contact is disclosed which is formed from a single, integral piece of sheet metal and includes an active contact element, a terminal element and a hood. The hood covers at least the active contact element to protect the pin-engaging tines formed integrally therewith from inadvertant distortion or breakage.

BACKGROUND OF THE INVENTION

The present invention relates generally to electrical contacts and, moreparticularly, to a one-piece electrical contact fabricated from asingle, integral piece of sheet metal. The contacts of the presentinvention may be characterized as hooded, socket contacts which areadapted to receive a compatible mating pin contact and are typicallyused in a variety of different electrical connector assemblies.

For several years demand has been increasing in the transportation,communication and data processing industries for electrical connectorscapable of withstanding severe environmental conditions while retainingor even improving their serviceability. In response to this demand, avariety of connectors have been developed having means to effectivelyseal the contacts within the connector shell while still enablingremoval and reinstallation of an individual contact should maintenanceof the connector so require. One approach to this problem has been toseal the rearward or conductor-receiving end of the connector componentswith an elastomeric grommet, the individual contacts being forcedthrough restrictive apertures in the grommet during installation orremoval. Typical examples of such connectors are illustrated in U.S.Pat. Nos. 3,336,569; 3,512,119; 3,786,397; and 3,960,428. One of thedisadvantages attendant to the use of these connectors is that thecontacts may be damaged during installation, or alternatively, thegrommet might be cut or torn, impairing the quality of the sealobtained. This is particularly troublesome with socket contacts havingsmall resilient fingers or tines stamped from the body of the socket.

In addition, increasing demands have been made to reduce the size ofthese electrical connectors and therefore, the contacts used in them arecorrespondingly small and subject to damage during handling andinstallation.

In order to overcome these problems, the contacts used in theseconnectors, and particularly the socket contacts, have been providedwith hoods to protect the active contact element of the contact, i.e.,the tines, from damage during handling and installation. The hood alsoprevents inadvertant displacement of the active contact element beyondits elastic limits which would require replacement of the contact.

The conventional hooded contact known in the art is constructed from atleast two pieces, one being the contact itself which may be fabricatedfrom sheet metal stock and the other being the hood which is generallyfabricated by center milling a suitably sized bar stock on a screwmachine. Of course, this dual fabricating process is not only timeconsuming and expensive, but it requires assembly of the componentsafter fabrication which further increases labor costs.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an electrical contactfor use in a connector assembly which provides all the advantages ofconventional multi-component hooded contacts without engendering theattendant disadvantages of increased manufacturing time and costs. Thecontact is fabricated by stamping and forming operations from a single,integral piece of sheet metal and includes an active contact element forelectrically engaging a compatible pin contact, a terminal element forreceiving and terminating an electrical conductor, and hood means forhousing and protecting the active contact element. Thus, the fragilecomponents of even very small socket contacts are fully protected duringshipment, installation and while in use within the connector. The holdalso includes an outer surface which is relatively smooth and free ofedges which might cut or tear the connector seals or grommets.

A principal feature of the present invention, therefore, is theprovision of a one-piece hooded contact fabricated from a single,integral piece of sheet metal.

Another feature of the present invention is the provision of a one-piecehooded socket contact with a crimp-type terminal element having positiveconductor locating and visual inspection means.

Still another feature of the present invention is the provision of aone-piece hooded socket contact having access apertures in the hood topermit inspection and presetting of the tines of the active contactelement.

A further feature of the present invention is the ability to massproduce a contact at low cost and increased production rates which meetsthe performance requirements and specifications prevalent in theconnector industry at this time.

Another feature of the invention is the provision of a one-piece hoodedsocket contact free of external grommet cutting edges.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features that are believed to be characteristic of theinvention are set forth in the appended claims. The invention itself,however, together with further objects and and attendant advantagesthereof, will be best understood by reference to the followingdescription taken in connection with the accompanying drawings in which:

FIG. 1 is a top plan view of a single integral sheet metal blank fromwhich the hooded socket contact comprising a first preferred embodimentof the present invention is formed;

FIG. 2 is a top plan view of the one-piece blank shown in FIG. 1 afterthe blank has been folded during an early stage in forming operation;

FIG. 3 is a top plan view of the folded one-piece blank shown in FIG. 2illustrating an intermediate stage wherein the blank is being rolledinto a tubular socket contact;

FIG. 4 is a top plan view showing the one-piece hooded electrical socketcontact of the first preferred embodiment of the present invention whichis formed from the blank shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along lines 5--5 in FIG. 1;

FIG. 6 is a cross-sectional view taken along lines 6--6 in FIG. 2;

FIG. 7 is a cross-sectional view taken along lines 7--7 in FIG. 3;

FIG. 8 is a cross-sectional view taken along lines 8--8 in FIG. 4;

FIG. 9 is a cross-sectional view taken along lines 9--9 in FIG. 4;

FIG. 10 is a fragmented sectional view taken along lines 10--10 in FIG.4 and showing in greater detail a preferred terminal element structure;

FIG. 11 is the view shown in FIG. 10 with the wire locating memberdisposed in the terminal element of the contact in the final operativeposition;

FIG. 12 is a fragmented top plan view of an alternative embodiment ofthe socket contact shown in FIG. 4 wherein a tubular sleeve is employedas a part of the terminal element of the contact;

FIG. 13 is a fragmented sectional view taken along lines 13--13 in FIG.12;

FIG. 14 is a fragmented partial perspective view of another alternativeembodiment of the socket contact shown in FIG. 4 illustrating anotherterminal element of the contact;

FIG. 15 is a sectional view taken along lines 15--15 in FIG. 14;

FIG. 16 is a top plan view showing a one-piece sheet metal blank used infabricating a socket contact in accordance with another preferredembodiment of the present invention;

FIG. 17 is a top plan view illustrating an early stage of the formingoperation in which the tines of the active contact element are arcuatein shape and bent upwardly from the portion of the blank comprising thehood of the completed tubular socket contact;

FIG. 18 illustrates an intermediate stage of the forming operation;

FIG. 19 illustrates a later stage of the forming operation wherein theblank shown in FIG. 16 is being formed into a tubular configuration;

FIG. 20 is a top plan view showing the completed socket contact formedfrom the one-piece blank shown in FIG. 16;

FIG. 21 is a cross-sectional view taken along lines 21--21 in FIG. 16;

FIG. 22 is a cross-sectional view taken along lines 22--22 in FIG. 17;

FIG. 23 is a cross-sectional view taken along lines 23--23 in FIG. 18

FIG. 24 is a cross-sectional view taken along lines 24--24 in FIG. 19;and,

FIG. 25 is a cross-sectional view taken along lines 25--25 in FIG. 20.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1 through 11 of the drawings, a first preferredembodiment of a one-piece hooded socket contact 10 for an electricalconnector assembly is shown at various stages of fabrication from aone-piece sheet metal blank. In this embodiment, the single, integralcontact blank 11 comprises a first rectangular portion, identifiedgenerally at 13, which forms the outer hood or shell of the socketcontact shown in FIG. 4, and a second, narrower rectangular portion,identified generally at 15, which forms an inner liner. For purposes ofillustration, a dashed line 17 is shown in FIG. 1 to define the juncturebetween the hood portion 13 and the liner portion 15.

As hereinafter described in greater detail, the socket contact 10 shownin FIG. 4 is formed from the contact blank 11 by first folding theblank, as illustrated in FIG. 2, until the hood portion 13 and thelinear portion 15 are juxtaposed and then, in a subsequent operation asillustrated in FIG. 3, rolling the folded blank into a tubularconfiguration.

The socket contact 10 shown in FIG. 4 includes a pin contact receivingend, identified generally at 19, and a conductor terminating end,identified generally at 21. Tines 23 and 25 are provided at the forward,or pin-receiving, end of the liner portion 15 and together comprise theactive contact element of the contact, in that these componentsresiliently engage a compatible pin contact of a mating connector bodyand are also the only components of the contact which move in the normaloperation of the connector. The tines 23 and 25 are defined by slots 27and 29, respectively, stamped in the blank 11 and extend forwardlywithin the contact 10 toward the pin-receiving end 19. A precious metalsuch as gold may be deposited or otherwise provided in a strip acrossthe blank 11 on the inner surfaces of the tines 23 and 25.Alternatively, the entire liner portions 15 may be plated with theprecious metal prior to the forming operations.

Apertures 35 and 37 in the hood portion 13 are located such that whenthe blank 11 is folded and rolled into the tubular contact socket theapertures are coincident with the tines 23 and 25. These aperturesprovide access through the hood of the socket contact to the tines topermit the tines to be set or pushed inwardly to thereby exert therequisite pressure on a pin contact inserted into the pin-receiving endof the socket contact.

A preferred terminal end used in conjuction with the hooded socketcontact 10 is a closed crimp barrel as illustrated in FIGS. 1-11. Sincethe hood portion 13 and the liner portion 15 are of generally equallength in this embodiment the terminal end 21 is, in effect, adouble-walled crimp barrel.

An aperture 39 in the hood portion 15 overlies a tab 41 in the linerportion 15 when the blank 11 is formed into the contact 10. The aperture39 permits the tab 41 to be bent inwardly as shown in FIG. 11 to form astop against which the conductor will abut as it is inserted into theterminal end 21. An aperture 43 is formed in the liner portion when thetab 41 is bent inwardly and is aligned with the aperture 39 in the hoodportion. Accordingly, the conductor is visible within the terminalelement to allow inspection to ascertain whether the conductor isproperly seated therein against the stop tab 41. The inner surface 45 ofthe outer end of the liner portion is beveled, thereby permitting thesmooth insertion of the wire conductor in the crimp barrel 21 andeliminating any sharp edges which might otherwise cut or score theconductor. A standard crimping machine may be used to crimp the closedcrimp barrel so that the conductor is firmly interconnected bothelectrically and mechanically to the contact 10.

As illustrated in the drawings, to conform the contour of the socketcontact 10 to the dimensions of the insert cavity in which the contactis located in the connector assembly, the width of the blank 11 iscorrespondingly varied. That is, where a smaller diameter is required,the width of the blank is correspondingly decreased. It follows,therefore, that the width along the corresponding section of the linerportion 15 underlying the hood portion 13 must be decreased to followthe contour of the hood portion. Moreover, it can be seen in FIG. 2 thatthe liner portion 15 is .[.substnatially.]. .Iadd.substantially.Iaddend.narrower than the hood portion 13 so that the respective edgesof the liner portions 15 will abut without overlapping, as will therespective edges of the hood portion 13, when the folded blank is rolledinto the completed socket contact.

Flanges 47 and 49 may be included on opposite sides of the hood portion13 to provide an optional retaining shoulder 51 when the socket contactis formed. The retaining shoulder 51, best seen in FIG. 4, allows thesocket contact to be used with existing connectors wherein a retainingshoulder is necessary to releasably mount the socket contact in thepocket of the connector body. Thus, during an early stage in themanufacture of the socket contact, a U-shaped ridge 51 is embossedacross the hood portion 13 in alignment with the retaining shoulderflanges 47 and 49. When the blank is subsequently folded, as illustratedin FIG. 2, and then rolled to form the tubular contact as illustrated inFIGS. 3 and 4, the retaining shoulder 51 is formed.

Accordingly, the hooded socket contact of the embodiment shown in FIGS.1-11 includes full-length liner within the hood and which has integraltines extending forwardly toward the pin contact receiving end. The hoodnot only protects the tines but also prevents the entry of oversized pincontacts in the socket contact.

When the barrel 21 is crimped to terminate the conductor in the socketcontact 10, the edges of the crimp barrel may be displaced as the crimpbarrel is distorted. Accordingly, when the contact is to be insertedinto a connector member or if it subsequently becomes necessary toremove the contact from the connector member, the standard tool commonlyused to insert and withdraw the contact from the connector member maynot fit over the crimp barrel 21 of the contact. Thus, the edges of thehood portion 13 may be welded, as indicated at 53, to prevent thedisplacement of the hood portion edges from their normal abuttingrelationship. It may also be desirable to form the blank 11 such thatthe seam of the hood portion is circumferentially displaced from theseam of the liner portion to expedite the welding operation.

Undesirable deformation of the closed crimp barrel of the socket contactmay be avoided without welding by utilization of a sleeve 55 coaxiallymounted on the crimp barrel as illustrated in FIGS. 12 and 13. There,the liner portion is shortened as indicated by dashed line 57 in FIG. 1,and the hood portion 13 of the blank is narrowed to reduce the diameterof the contact along the portion of the crimp barrel identifiedgenerally at 59. The tubular sleeve 55 is slipped onto the crimp barrel21 of the contact 10, and after the sleeve is seated on the crimp barrelportion 59, the end of the crimp barrel is flared, as illustrated at 61,to prevent its accidental removal.

In another embodiment illustrated in FIGS. 14 and 15, the liner portion15 extends beyond the hood portion 13 forming an open crimp barrel 63 atthe terminal end of the contact 10. In particular, the cross-section ofthe open crimp structure 63 is generally U-shaped before being crimpedonto the conductor and is formed as an integral portion of the liner 15.The structure 63 may also include a first portion 65 for engaging thebare conductor to make electrical contact therewith and a second outerportion 67 for engaging and holding the insulation to provide strainrelief.

Another preferred embodiment of the present invention is illustrated inFIGS. 16 through 25, inclusive. The particular embodiment of the socketcontact shown therein is also formed from a one-piece blank 71, but theblank is rolled, without lengthwise folding, to form the hooded contact.More particularly, the contact 70 formed from the contact. Moreparticularly, the contact 70 formed from the blank 71 comprises a hood72 having a forward pin-receiving portion 73 and rearwardly-disposedwire-engaging crimp barrel 75. Tines 77 and 79 are spaced from the sidesof the blank along the forward pin-engaging portion 73 thereof in theforward direction, the rear or base ends of the lines being coupled tothe liner portion 80 which is formed from flange portions, identifiedgenerally at 81 and 83.

The contact is assembled as illustrated in FIGS. 17 through 25 by firstbending the flange portions 81 and 83 upwardly so that the tines 77 and79 are above the remainder of the blank 71 at substantially right angleswith respect to the hood portion 72 of the blank. The tines 77 and 79are then rolled to have an inwardly directed arcuate shape and bent overthe blank 71 until the contact tines 77 and 79 and flanges 81 and 83rest adjacent the upper surface of the hood portion 72, as shown inFIGS. 18 and 23. The blank 71 is then rolled as illustrated in FIG. 19and the cross-sectional view of FIG. 24, until finally, the blank 71 isrolled into the substantially tubular contact member 70 shown in FIGS.20 and 25.

The completed socket contact 70 shown in FIGS. 20 and 25 comprises anouter hood 72 and a liner portion having a pair of forwardly directedtines 77 and 79 for engaging a corresponding pin contact member in theforward pin-receiving portion 73. Apertures 85 and 87 in the forwardportion of the hood are initially located in the blank 71 to be alignedwith the tines 77 and 79, respectively, in the fabricated socket contact70. The tines 77 and 79 are thereby accessible through the correspondingaperture 85 or 87 to be set or bent for engagement with a given pincontact.

The socket contacts of the several preferred embodiments of the presentinvention illustrated herein have the advantage that they are all formedfrom a one-piece integral blank of sheet metal which is formed into aunitary contact having a forward active contact element and a rearwardconductor terminating element and a hood which encloses and protects theactive contact element. By use of a one-piece blank, a plurality ofcontacts can be stamped from a continuous strip of sheet material andformed into the required tubular shape. In addition, only the tineportions need be plated for better electrical contact, reducing the costof plating larger portions of the contact as heretofore was required.

The contact blanks 11 and 71 illustrated herein are initially stampedfrom a sheet of thin metal such as cadmium copper or beryllium copper.Although only one such blank is shown in each of FIGS. 1 and 16, it willbe understood that a plurality of said blanks may be stamped fromcontinuous lengths of the thin sheet metal with the several blanks beinginterconnected by thin strips or webs of the metal to facilitate thestamping and handling of the blanks in production quantities.Thereafter, the contact blanks are separated from the strips prior to orduring the operation performed in making socket contacts from theblanks. Alternatively, the contacts may be left in continuous strips andwound on reels for use with automatic contact terminating machines.

As used herein, including in the appended claims, directional terms suchas "forward," "rearward," and the like, refer to the particular positionof the blanks and contacts shown in the drawings. It should beunderstood, however, that this terminology has been employed only forconvenience in description, and, in fact, the contact can be made andused in virtually any desired orientation.

It will also be appreciated by those skilled in the art that the socketcontacts 10 and 70, illustrated in FIGS. 4 and 20, have hood portionswith external surfaces which are relatively smooth and free of any sharpedges. These hood portions facilitate passage of the contact through therestrictive apertures in the rearward sealing grommets of conventionalconnectors without cutting or tearing the grommet. Specifically, thereis no exposed edge that runs longitudinally along the contact whichmight slice into the grommet during installation or removal.

Of course, it should be understood that various changes andmodifications to the preferred embodiments described herein will beapparent to those skilled in the art. Such changes and modifications canbe made without departing from the spirit and scope of the presentinvention and without diminishing its intended advantages. It is,therefore, intended that such changes and modifications be covered bythe following claims.

I claim:
 1. An elongated electrical contact formed of a single, integralpiece of sheet metal and comprising:an active element forming an openend at one end of the contact including .Iadd.cantilevered.Iaddend.radially resilient tine means for electrically engaging acomplimentary pin contact; an integral terminal element forming an openend at the other end of the contact including means for mechanically andelectrically engaging an electrical conductor; and an open ended hoodmeans .Iadd.extending .Iaddend.coaxially about .Iadd.and continuouslyaround .Iaddend.said active contact element for housing and protectingsaid active contact element, said hood means including a relativelysmooth outer surface free of cutting edges .Iadd.with substantially allpoints on the outer surface of said active contact element beingcontiguous with the inner surface of said hood means.Iaddend..
 2. Theelectrical contact of claim 1 wherein said active contact element andsaid terminal element form the opposite ends of an integral tubularliner portion and said hood means comprises a tubular hood portiondisposed coaxially over said active contact element and integrallycoupled with said liner portion at said one end of the contact.
 3. Theelectrical contact of claim 2 wherein said terminal element comprises aclosed crimp barrel and includes a conductor locating tab having a baseintegrally coupled to said liner portion and a distal end extendingradially inwardly therefrom, and said hood portion extends coaxiallyover said crimp barrel and includes a visual inspection aperturecoincident with said locating tab.
 4. The electric contact of claim 2wherein said hood portion also includes an annular, radially outwardlyextending shoulder.
 5. The electrical contact of claim 2 wherein saidtine means comprises at least one cantilevered tine having a baseintegrally coupled to said liner portion and a distal end extendinginwardly therefrom and forwardly toward said one end.
 6. The electricalcontact of claim 5 wherein said tine means includes two diametricallyopposed cantilevered tines.
 7. The electrical contact of claim 1 furtherincluding a liner portion and wherein said active contact elementcomprises at least one cantilevered tine integral with and extendingfrom said liner portion forwardly toward said one end, and said hoodmeans comprises a tubular hood portion disposed coaxially over saidliner portion and said tine and extending rearwardly from said linerportion toward said other end to thereby form said terminal element. 8.The electrical contact of claim 7 wherein said hood portion isintegrally coupled with said liner portion at said one end of thecontact.
 9. The electrical contact of claim 8 wherein said hood portionis integrally coupled with said liner portion along a longitudinallyextending seam intermediate the ends of said contact.
 10. A one-pieceelectrical contact formed of a single, integral piece of sheet metalcomprising:a tubular liner portion; a tubular hood portion coaxiallyoverlying said liner portion and integrally coupled to said linerportion at a forward pin-receiving end, said portions having an oppositeopen end for receiving and terminating a wire conductor; and at leastone tine; said liner portion having a slot in which said tine extendsinwardly from said liner and forwardly toward said pin-receiving end,and said hood portion having an access aperture coincident with saidtine to permit said tine to be displaced inwardly with respect to saidliner portion.
 11. The one-piece electrical contact of claim 10 whereinsaid liner portion includes a second tine and wherein said hood portionhas a second access aperture coincident with said second tine, saidtines being located on opposite sides of said liner portion.
 12. Theone-piece hooded socket contact of claim 10 wherein said liner portionextends rearwardly beyond the end of said hood portion and includes anopen generally U-shaped crimp structure beyond said hood portion toreceive said wire conductor.
 13. The one-piece electrical contact ofclaim 10 wherein said liner portion extends the length of said hoodportion to provide within said hood portion a closed crimp barrel atsaid opposite end for receiving said wire conductor.
 14. The one-pieceelectrical contact of claim 13 including a tab stamped in said linerportion and wherein said hood portion has a viewing aperture coincidentwith said tab, said tab extending inwardly from said liner portion toprovide means for locating said wire conductor in said crimp barrel,said viewing aperture permitting visual inspection of said wireconductor in said crimp barrel.
 15. A one-piece tubular hooded socketcontact formed from a unitary piece of sheet metal and adapted toreceive a pin contact at one end and to terminate an electricalconductor at the opposite end, said one-piece contact comprising:atubular hood portion having a forward open pin-receiving end and arearward end including a crimp barrel for receiving said conductor; aplurality of tines extending forwardly in said tubular hood portion,said tines having a concave cross-sectional configuration forcooperating with said pin contact; and a plurality of longitudinalintegral flanges disposed intermediate said ends of the tubular hoodportion, each of said flanges integrally coupling one of said tines tosaid hood portion along a longitudinally extending seam of said contact.16. An electrical contact formed of a single, integral piece of sheetmetal and comprising:a tubular liner portion having an active contactelement at one end including resilient tine means for electricallyengaging a complementary pin contact and a terminal element at theopposite end including means for mechanically and electrically engagingan electrical conductor; and hood means for housing and protecting saidactive contact element, said hood means comprising a tubular hoodportion disposed coaxially over said active contact element andintegrally coupled with said liner portion at said one end of thecontact, said hood portion including a relatively smooth outer surfacefree of cutting edges, and said hood portion including an accessaperture coincident with said tine means of said active contact element.